The article “Flexible modellbasierte Montageprüfung” published by the Fraunhofer-Institut für Fabrikbetrieb und —automatisierung IFF in Magdeburg, downloadable at www.iff.fraunhofer.de/de/geschaeftsbereiche/messtechnikprueftechnik/montagepruefung-modellbasiert.htl, describes a known assembly completeness inspection method. In this method, a digital camera takes a large quantity of pictures of different sections of a finished assembly. Each recorded picture is then compared to a synthetic picture of how the respective section of the assembly should look like. The synthetic picture is obtained from the CAD-data representing the assembly. Thus, elements of the assembly, which have not been correctly mounted or which are even absent, can be spotted.
Using this known method to inspect large assembled structures, such as car bodies of railway vehicles, is very time consuming. Indeed, in such a case, the digital camera needs to be moved around the whole structure to take a large amount of pictures of small sections of the structure.
Furthermore, this known method involves projecting a strip pattern onto the sections of the structure that are to be pictured. The accurate reflection of the strip pattern is important to obtain a high quality picture. Accordingly, this method is not well adapted to steel structures because such strip patterns are not well reflected by steel.